<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="https://unpkg.com/vue@3/dist/vue.global.js"></script>
</head>
<body>
  <div id="Application">
    <div class="container" @mousemove.stop="move">
      <div class="ball" :style="{left: offsetX + 'px', top: offsetY + 'px'}"></div>
    </div>
  </div>

  <script>
    const { createApp, ref } = Vue;
    let config = {
      setup() {
        const offsetX = ref(0);
        const offsetY = ref(0);
        const move = (event) => {
          if (event.clientX + 30 > 440) {
            offsetX.value = 440 - 60;
          } else if (event.clientX - 30 < 0) {
            offsetX.value = 0;
          } else {
            offsetX.value = event.clientX - 30;
          }
          if (event.clientY + 30 > 440) {
            offsetY.value = 440 - 60;
          } else if (event.clientY - 30 < 0) {
            offsetY.value = 0;
          } else {
            offsetY.value = event.clientY - 30;
          }
        };
        return {offsetX, offsetY, move};
      },
    };
    createApp(config).mount("#Application");
  </script>

  <style>
    body {
      margin: 0;
      padding: 0;
    }
    .container {
      margin: 0;
      padding: 0;
      position: absolute;
      width: 440px;
      height: 440px;
      background-color: blanchedalmond;
      display: inline;
    }
    .ball {
      position: absolute;
      width: 60px;
      height: 60px;
      left: 100px;
      top: 100px;
      background-color: red;
      border-radius: 30px;
      z-index: 100;
    }
  </style>
</body>
</html>